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The Early Days ( sometimes it is better to be lucky than good ) Gulf of Mexico platforms built around 1946 – 48 typically had deck heights 20 to 40 feet above mean sea level Gulf of Mexico platforms built around 1946 – 48 typically had deck heights 20 to 40 feet above mean sea level Consultants’ evaluations: Consultants’ evaluations: “in 100 feet of water waves will probably seldom, IF EVER, exceed 20 feet in height” “in 100 feet of water waves will probably seldom, IF EVER, exceed 20 feet in height” “ … settled on a maximum wave height of about 25 feet and a recommended deck height of 32 feet” “ … settled on a maximum wave height of about 25 feet and a recommended deck height of 32 feet” Consensus: maximum wave ~ 29 feet, occurring perhaps once every 40 to 50 years. Consensus: maximum wave ~ 29 feet, occurring perhaps once every 40 to 50 years. Very loose “consensus” – no API guidance, little regulation. Very loose “consensus” – no API guidance, little regulation.

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Luck Starts to Run Out 1947 – 1952: series of relatively weak, small hurricanes in the Gulf 1947 – 1952: series of relatively weak, small hurricanes in the Gulf October 1949 – platform off Freeport damaged – post-mortem suggested waves as high as 40 feet. October 1949 – platform off Freeport damaged – post-mortem suggested waves as high as 40 feet. Observed damage in others led to estimates of feet – calls into question both the upper limit and frequency of occurrence of high waves in Gulf Observed damage in others led to estimates of feet – calls into question both the upper limit and frequency of occurrence of high waves in Gulf Leads to stronger designs for a few operators Leads to stronger designs for a few operators

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Lulled to Sleep? All Hurricanes and Trop Storms in Gulf

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Luck Starts to Run Out 1956 – Hurricane Flossie 1956 – Hurricane Flossie A Category 1 storm A Category 1 storm 50 men rode out the storm in the Gulf. One vessel lost its anchor and floated around during the storm in keeping with a philosophy of “taking a calculated risk that they would be safe.” 50 men rode out the storm in the Gulf. One vessel lost its anchor and floated around during the storm in keeping with a philosophy of “taking a calculated risk that they would be safe.” Led to calls for complete evacuation in hurricanes. Led to calls for complete evacuation in hurricanes.

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Luck Starts to Run Out 1957 – Hurricane Audrey 1957 – Hurricane Audrey Forms in Gulf – now called “Sudden storms” Forms in Gulf – now called “Sudden storms” One mobile drilling rig sank, with four tenders suffering damage when pulled loose from their mooring and running aground One mobile drilling rig sank, with four tenders suffering damage when pulled loose from their mooring and running aground Industry record of no fatalities held. Industry record of no fatalities held.

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Industry Intensifies Action 1957 – Hurricanes Audrey and Bertha – three significant storms in 2 years – Hurricanes Audrey and Bertha – three significant storms in 2 years. API forms “Advisory Committee on Fundamental Research on Weather Forecasting.” API forms “Advisory Committee on Fundamental Research on Weather Forecasting.” Disbanded in Disbanded in Why? Other issues and Gulf fairly quiet (Carla in 1961 but it hits Texas) Why? Other issues and Gulf fairly quiet (Carla in 1961 but it hits Texas)

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Hmmmm? All Hurricanes and Trop Storms in Gulf

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No Consensus Deck height practices: Deck height practices: Varied from the 1950 era standard of 28 – 32 feet above mean Gulf level to higher than 50 feet. Varied from the 1950 era standard of 28 – 32 feet above mean Gulf level to higher than 50 feet. Not coincidently, those using higher values were companies directly impacted by storms either in terms of property or direct threat to employees. Not coincidently, those using higher values were companies directly impacted by storms either in terms of property or direct threat to employees. Higher meant safer and more expensive – “each company placed a bet on the right combination of safety and cost”. Higher meant safer and more expensive – “each company placed a bet on the right combination of safety and cost”. (Primitive cost-benefit analysis)

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Luck Runs Out : Hurricane Hilda – Category : Hurricane Hilda – Category 4 Hilda was the most damaging tropical cyclone to the offshore oil industry, at the time of its impact. Hilda was the most damaging tropical cyclone to the offshore oil industry, at the time of its impact. More than US$100 million in losses. More than US$100 million in losses. 13 oil platforms were destroyed 13 oil platforms were destroyed 5 more damaged beyond repair [ 5 more damaged beyond repair [ [

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Some “Good Luck”, Some Bad 1969: Hurricane Camille 1969: Hurricane Camille ODGP measured a wave between 70 and 75 feet high!!! Used to calibrate hindcast models in Gulf for decades. Metocean criteria developed using those hindcasts as database of storms in Gulf.

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API Standards and Design Waves First API offshore standard (RP2A) issued in 1969 First API offshore standard (RP2A) issued in 1969 No design wave information until 7 th edition in No design wave information until 7 th edition in Recommends use of “the 100-year wave”Recommends use of “the 100-year wave” To this point the owner chose the return period and the use of both 25 and 100 year values was common. To this point the owner chose the return period and the use of both 25 and 100 year values was common. 1% risk of exceedance annually = 100 yr1% risk of exceedance annually = 100 yr 4% risk of exceedance annually = 25 yr4% risk of exceedance annually = 25 yr

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API Standards and Design Waves 20th edition (1993) includes a new wave force calculation “recipe” that substantially changes that of the 19 th edition (1991) 20th edition (1993) includes a new wave force calculation “recipe” that substantially changes that of the 19 th edition (1991) Design (“100-year”) wave conditions changed as well Design (“100-year”) wave conditions changed as well

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WOW! 1992 saw Hurricane Andrew 1992 saw Hurricane Andrew

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What Hath Andrew Wrought? Category 4 storm in Gulf Category 4 storm in Gulf MMS estimates 700 structures took “significant” hit MMS estimates 700 structures took “significant” hit 22 older platforms destroyed 22 older platforms destroyed 65 others with significant damage 65 others with significant damage Majority had been designed to 25 year values and 35 to 40 foot decks Majority had been designed to 25 year values and 35 to 40 foot decks Newer platforms that were designed with decks to pass up to 72 foot waves had only minor damage Newer platforms that were designed with decks to pass up to 72 foot waves had only minor damage

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Effect of Andrew and New API Force Recipe Gave a boost of energy to an API committee looking at assessment of existing platforms Gave a boost of energy to an API committee looking at assessment of existing platforms Task group decided that the new criteria should be relaxed for existing platforms and consideration be given to CONSEQUENCE OF FAILURE Task group decided that the new criteria should be relaxed for existing platforms and consideration be given to CONSEQUENCE OF FAILURE Willing to take higher risks with older assets in part because cost to modify/replace are too high Willing to take higher risks with older assets in part because cost to modify/replace are too high

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Consequence-based Criteria for New-Build Platforms CBC for assessing existing platforms in place in 1996 (issued as a supplement to the 20 th edition of RP2A. CBC for assessing existing platforms in place in 1996 (issued as a supplement to the 20 th edition of RP2A. Sets stage for introducing this concept for new-build Sets stage for introducing this concept for new-build L1 L1 L2 L2 L3 L3

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2005 Atlantic Season: most active in recorded history 2005 Atlantic Season: most active in recorded history 28 named storms, 15 hurricanes, 7 major hurricanes, and four category 5 hurricanes ( per NOAA NHC ) 28 named storms, 15 hurricanes, 7 major hurricanes, and four category 5 hurricanes ( per NOAA NHC ) Worst season previously: 1933 with 21 named storms, 10 hurricanes, and 5 major hurricanes Worst season previously: 1933 with 21 named storms, 10 hurricanes, and 5 major hurricanes

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Impact of Ivan, Katrina, and Rita was worst two year period (23 hurricanes) since (21 total) was worst two year period (23 hurricanes) since (21 total) Lots of damage to platforms and mobile rigs (114 platforms destroyed in Katrina and Rita) Lots of damage to platforms and mobile rigs (114 platforms destroyed in Katrina and Rita) Lots of infrastructure damage (pipelines) leading to loss of oil and gas production Lots of infrastructure damage (pipelines) leading to loss of oil and gas production

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API Metocean Reaction Study of Ivan led to conclusion it was a rare event statistically but no need for significant criteria revision (OTC Paper 17740) Study of Ivan led to conclusion it was a rare event statistically but no need for significant criteria revision (OTC Paper 17740) Recommendation was to simply include Ivan in any extremal analysis Recommendation was to simply include Ivan in any extremal analysis Maximum Hs (m): Maximum Hs (m): Ivan16.0 Ivan16.0 Katrina16.9 Katrina16.9 Rita11.5 Rita11.5 API Criteria before these storms? Hmax = 21.5 m Hs ≈ 12.6 m

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Industry and API Metocean Reaction The rapid-fire occurrence of three huge storms in two years led to significant revisions in part due to a mooring risk JIP led by ABS which required the best possible metocean data The rapid-fire occurrence of three huge storms in two years led to significant revisions in part due to a mooring risk JIP led by ABS which required the best possible metocean data Several key findings: Several key findings: Loop current and or Loop eddies provided get source of energy for all three of these stormsLoop current and or Loop eddies provided get source of energy for all three of these storms Dividing the Gulf into four regions was deemed appropriateDividing the Gulf into four regions was deemed appropriate Use of the full 1990 – present hurricane database was not appropriateUse of the full 1990 – present hurricane database was not appropriate

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Bias in Storms Prior to 1950 Measurements were sparse, often only at land stations. What went on in the Gulf was speculative. Measurements were sparse, often only at land stations. What went on in the Gulf was speculative. In a 2006 paper (OTC 18418), Cooper and Stear concluded that there was a negative bias in the 1900 to 1949 storms as characterized by the National Hurricane Center. In a 2006 paper (OTC 18418), Cooper and Stear concluded that there was a negative bias in the 1900 to 1949 storms as characterized by the National Hurricane Center.

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Bias in Storms Prior to 1950 Plots: 6 pre-’50; 16 post-’50 storms Pre-’50, 70% of storms show no drop as they near coast Post-’55, 12% show no drop Suggest: pre-’50 applied coastal data offshore resulting in low bias Other factors support conclusion: NOAA generally does not use pre-’50 8 of top 10 winds occurred post-’50 7 of top 10 waves occurred post-’50 Plots provided by Chevron Energy Technology Company

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Measured Data is Foundational Hindcasts are used to generate criteria BUT these are calibrated against data Hindcasts are used to generate criteria BUT these are calibrated against data Excellent network of data buoy in Gulf and along coast

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Future Hurricanes More/less? More/less? Stronger? Stronger? Similar tracks? Similar tracks? Was the season a precursor of things to come? Was the season a precursor of things to come?

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Future Hurricanes Was the season a precursor of things to come? Was it all that unusual? Was the season a precursor of things to come? Was it all that unusual? How confident can we be in the historical record? How confident can we be in the historical record? Prior to about 1950 – no air reconnaissancePrior to about 1950 – no air reconnaissance Satellites much laterSatellites much later

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Future Hurricanes Key factors: warm water and wind shear generally considered most important Key factors: warm water and wind shear generally considered most important Area of much current research AND considerable controversy Area of much current research AND considerable controversy “Experts” do not agree “Experts” do not agree Models do not agree Models do not agree

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Future Hurricanes and API As opposed to the general historical pattern of API, being REACTIVE, there is a shift to being more PROACTIVE As opposed to the general historical pattern of API, being REACTIVE, there is a shift to being more PROACTIVE Funding a synthetic hurricane study at a cost significantly larger than “normal” API-funded research to develop a long term ( yrs) synthetic data base of hurricanes in the Gulf Funding a synthetic hurricane study at a cost significantly larger than “normal” API-funded research to develop a long term ( yrs) synthetic data base of hurricanes in the Gulf Supportive of National Center for Atmospheric Research (NCAR) modelling work on how climate change is likely to influence hurricane activity through 2055 through RPSEA with Industry reps on steering committee, members’ time, etc. Supportive of National Center for Atmospheric Research (NCAR) modelling work on how climate change is likely to influence hurricane activity through 2055 through RPSEA with Industry reps on steering committee, members’ time, etc.

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Future Hurricanes and API No criteria changes to account for any future climate scenario being applied in part due to uncertainties No criteria changes to account for any future climate scenario being applied in part due to uncertainties May be applied when the results of the sponsored research efforts are finished May be applied when the results of the sponsored research efforts are finished

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QUESTIONS ?

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BACKUP

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TABLE 2 – LIFE SAFETY LEVEL MANNING CONDITIONS EXPOSURE TO PERSONNEL 1 Manned, non- evacuated Platform continuously manned Platform continuously manned Evacuation prior to design event is not intended or is not feasible Evacuation prior to design event is not intended or is not feasible Personnel exposed to severe hurricanes Personnel exposed to severe hurricanes 2 Manned, evacuated Platform normally manned Platform normally manned Evacuation prior to design event is planned and feasible Evacuation prior to design event is planned and feasible Largest events that personnel are exposed to are a “sudden” hurricane or a winter storm Largest events that personnel are exposed to are a “sudden” hurricane or a winter storm 3Unmanned Platform normally unmanned except for day trips to perform short field operations Platform normally unmanned except for day trips to perform short field operations May have emergency shelter but no permanent quarters May have emergency shelter but no permanent quarters Personnel exposed to worst event that can occur during the day Personnel exposed to worst event that can occur during the day Occasional manning for short durations Occasional manning for short durations Short maintenance, construction, workover, or drilling Short maintenance, construction, workover, or drilling Scheduled to minimize potential hurricane exposure Scheduled to minimize potential hurricane exposure

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TABLE 3 – CONSEQUENCE OF FAILURE PLATFORM CATEGORY CONSEQUENCE OF FAILURE PLATFORM CHARACTERISTICS 1High Platform with major drilling, production, pipeline processing, or storage facilities Platform with major drilling, production, pipeline processing, or storage facilities Other platforms with high consequences of failure Other platforms with high consequences of failure Wells not shut-in during design event Wells not shut-in during design event Potential for well flow in the event of platform failure Potential for well flow in the event of platform failure All platforms in depths greater than 400 feet All platforms in depths greater than 400 feet 2Medium Platform with drilling or production pipeline facilities with medium consequences of failure Platform with drilling or production pipeline facilities with medium consequences of failure Wells shut-in during design event Wells shut-in during design event Wells protected by SSSV’s Wells protected by SSSV’s Oil storage limited to process inventory and “surge” tanks for pipeline transfers Oil storage limited to process inventory and “surge” tanks for pipeline transfers 3Low Small well protectors and caissons with small consequences of failure Small well protectors and caissons with small consequences of failure No more than 5 completions on or connected to platform No more than 5 completions on or connected to platform Wells shut-in during design event Wells shut-in during design event Wells protected by SSSV’s Wells protected by SSSV’s No more than 2 pieces of production equipment No more than 2 pieces of production equipment Oil storage limited to process inventory Oil storage limited to process inventory Maximum water depths of 100 feet Maximum water depths of 100 feet